Det finns vetenskapligt stöd som visar på att regelbunden fysisk aktivitet är bra både fysiskt och psykiskt men ett av de största problemen inom detta område är att få kunskap om hur människor på bästa sätt kan motiveras, speciellt ungdomar. Syftet med denna studie är att undersöka vad det är som motiverar ungdomar till träning. En kvantitativ metod användes med enkäter som delades ut till ungdomar på olika gym. Resultatet visade att ungdomarna motiverades av både inre och yttre motivationsfaktorer. Den mest förekommande motivationsfaktorn var målinriktad träning där målen kunde vara både fysiska, gå ner i vikt, och psykiska, bättre självförtroende. Den slutsats som kan dras är att det finns olika faktorer som påverkar ungdomarna till träning men yttre motivationsfaktorer är det mest förekommande faktorerna.

Master of Science

M.S.

This study investigated the determination of an optimal resistive force for use during a short-term, high-intensity cycling power test. Twenty-four college females [age (yrs) x̄=22.0 ± 0.50; weight (kg) x̄=60.3 ± 1.46] gave consent and participated in a 1 repetition maximum (RM) test of the leg extensors and 5 maximal 15 s cycling tests using a modified Monark cycle ergometer. The 1 RM test was performed using a Nautilus leg extensor machine. Even increments between six to ten % 1RM test were utilized to determine the resistive force applied to the flywheel. The 5 tests were divided into a 2 testing sessions occurring at least 48 h apart. Each subject warmed-up at 50 - 60 rpms for 2 - 5 minutes without resistance prior to testing. Each test consisted of a maximal cycling bout of 15 s with 20 minutes rest between tests. The variables measured included peak power (PP), time to peak power (TTPP), power fatigue rate (PFR), power fatigue index (PFI), and average power (AP). These values were collected by a microcomputer interfaced with the cycle ergometer. In general, PP decreased at a resistance greater than 9 % 1RM. The average reported PP values were 363±15, 413±19, 465±19, 520±21, and 460±41 for loads 6 to 10 % 1RM respectively. Similar results were reported for AP. The differences in PP for loads between 8 and 10 % 1RM were statistically different. Results show that PP varies based on loads of % 1RM and the optimal range is between 8 and 10% 1RM. / Master of Science

This study examined the effects of acute dehydration on repeated bouts of anaerobic cycling exercise. Eight college wrestlers performed 2 cycle ergometer trials before (hydrated, H) and 48 hrs after dehydration (D) via exercise, fluid restriction, and heat exposure. The trials consisted of a 4 min warm-up followed by 5, 10 s maximal bouts interspersed with 20 s rest intervals. The ergometer was preloaded with .1 kg/kg of H bodyweight. Peak power (PP,W), average power (AP,W), time to peak power (TTPP,s), power fatigue rate (PFR,W/s), and power fatigue index (PFI,%) were recorded by an integrated microcomputer. Pretrial plasma osmolality (PO), HTC, plasma electrolytes, and caloric intake (Kcal) were also measured. The wrestlers lost 4.5±1.0% (X±SD) bodyweight from H to D trials which increased PO and HTC (p<.01). There was a decline in plasma [K+] (p<.05) and no change in Kcal. PP values for H bouts 1-5 were 1004±54, 918±47, 809446, 727438, and 681±40 and for D bouts 1-5 were 937±52, 836±46, 766±40, 702±41, and 706±32 (X±SEM). AP results were similar to PP and thus not shown. There were no differences in H and D trials for TTPP, PFR, and PFI. After dehydration PP and AP were reduced during bouts 1-3 (p<.05) and appear to level in bouts 4 and 5 coinciding with H PP and AP. These results suggest that rapid dehydration by wrestlers causes a decrease in PP and AP production during initial bouts of repeated anaerobic exercise. With the onset of fatigue in later bouts PP and AP are unaffected. / Master of Science

This investigation used a constant-load cycle ergometer as a way of examining relationships between the cycle ergometer and sprint performance. Twenty-five college-aged males were used for this investigation. Following a three minute warm-up, each subject performed a 15 sec. maximal bout on the cycle ergometer. The resistance load on the ergometer was set at 0.12kg/kg of bodyweight. Peak power (PP), average power (AP), time to peak power (TTPP), power fatigue rate (PFR), and power fatigue index (PFI) were computed using a microcomputer system. In addition, PP,AP, and PFR were adjusted for total bodyweight (PP/kg, AP/kg, PFR/kg). On a separate day each subject performed six sprints two each at 50m, 100m, and 200m. Each sprint was electronically timed using an infra-red motion detector and starting blocks were used. Initially low correlations were found between the ergometer parameters and the sprint times (r=.07-.55). However upon closer evaluation stronger relationships appeared to exist for the faster subjects. Therefore, subject subgroups of faster subjects were formed. Subject subgroups for the 5 Om (T<7.5sec.), 100m (T<l4sec.)}, and 200m (T<26.6sec.) showed higher correlations (r=.06-.70). Further analysis revealed that high inter-variable correlations existed between many of the ergometer variables. Based on these correlations the parameters were separated into four groups. Group I contained variables of absolute power (PP,AP), group II were variables of relative power (PP/kg, AP/kg), group III contained variables of fatigue (PFR, PFI, PFR/kg), and group IV consisted of the acceleration variable (TTPP). Equations for predicting sprint performance were developed using one to four variables with only one variable from each group being used. The best equation was considered to be the one that yielded the highest r* value while also yielding the lowest Akakai Information Criteria value and MSE. Variables from the relative power group (PP/kg, AP/kg) and fatigue group (PFR, PFI, PFR/kg) were the best indicators of performance. These results suggest that the cycle ergometer used in this investigation can be used for evaluating the components of sprint performance in untrained males, and that this test is best when compared to the 200 m dash. / Master of Science

A growing body of research suggests that the respiratory system may be limited in its ability to meet the demands of increased ventilitory work. This is supported by studies reporting altered contractile properties of the diaphragm in response to increased ventilations. In order to determine if expiratory muscle function is affected by increased ventilitory demand, this study evaluated maximal expiratory pressure, PeMax, in response to two separate short-term, high-intensity exercise trials. Males (n=7) and females (n=5) not currently in active physical training underwent a VO₂ max test and a constant workload of 90% of VO₂ max. PeMax was measured at rest, immediately post exercise, and at one two and five minutes into recovery for both exercise trials. PeMax values were found to decrease 12% and 17% in response to graded and constant workload conditions respectively (P<.05), and this decline persisted throughout the five minute recovery. No Significant relationship was found between magnitude of decline in PeMax and VO₂ max or decline in PeMax and Ve max. These findings suggest that maximal graded exercise as well as exhaustive constant workload exercise corresponding to 90% of VO₂ max provide the ventilitory stimulus great enough to result in a decline in expiratory performance. / Master of Science

This study sought to examine the exercise-induced ST-segment shifts, J₀ and J₆₀, attributable to ECG lead configuration, specifically to evaluate if ischemic changes are modified as a function of using the Mason-Likar lead system. Males (N=30) referred for diagnostic testing underwent a symptom-limited graded exercise test (SLGXT). ST-segment shifts, J₀ and J₆₀, measured as the difference from baseline to recovery minute one, were not significantly different in responses measured from two simultaneous complexes for lead V₅. In frontal lead II, differences were found in the ST-segment response at baseline vs. recovery minute one. All ST-segment shifts were computed as the difference between J_x obtained at resting baseline vs. the J_x obtained at the exercise measurement in the same posture. ST-segment shifts, J₀ and J₆₀, measured at peak-exercise vs. recovery minute one using the Mason-Likar lead system, revealed a significant difference according to the measurement recorded in both leads V₅ and II (p<.05). Comparisons of frequencies for clinically abnormal ST-segment shifts according to ECG lead configuration at recovery minute one when measured from peak-exercise using Mason-Likar were significant in only lead II (p<.05). Observation of the data suggest that the Mason-Likar lead system may affect the interpretation of ischemic ST-segment shifts in lead II. However, these results do not invalidate the interpretation of ischemic ST-segment shifts in lead V₅ using the Mason-Likar lead system. / Master of Science

Thesis (Ph.D.)--University of Rhode Island, 2007. / Includes bibliographical references (leaves 230-245).

A incontinência urinária (IU) é uma disfunção prevalente em atletas do sexo feminino. A atividade física (AF) intensa tem sido identificada como um fator de risco para a IU, enquanto a AF moderada parece ter um efeito protetor. Contudo, o impacto de diferentes níveis de AF nos músculos do pavimento pélvico (MPP) tem sido pouco investigado. O objetivo desta tese foi analisar a prevalência da IU em atletas portuguesas de alta competição e identificar os seus potenciais fatores de risco. Pretendeu-se ainda analisar a associação entre o nível de AF e variáveis da função dos MPP. Foram efetuados 3 estudos transversais, em mulheres jovens e saudáveis com diferentes níveis de AF. Os dados foram recolhidos através de questionários, excepto os relativos às variáveis da função dos MPP tendo sido avaliadas através de manometria. Foi efetuada a análise estatística adequada aos objetivos em estudo, com ajuste para potenciais variáveis de confundimento. No estudo I, avaliou-se a prevalência e os fatores de risco da IU em 372 atletas de diferentes desportos e 372 controlos. No estudo II, investigou-se a associação dos Distúrbios Alimentares (DA) com a IU na mesma amostra. No estudo III, explorou-se a associação de diferentes níveis de AF com as variáveis da função dos MPP. Os resultados mostraram que: as atletas de alta competição apresentam um odds superior de IU em comparação com os controlos; as atletas com DA apresentaram maior probabilidade de IU de qualquer tipo, relativamente às atletas sem DA; o nível de AF associou-se com a pressão vaginal em repouso mas não com a força e a endurance dos MPP. Em conclusão, as atletas de alta competição apresentaram maior probabilidade de apresentar IU, sendo o risco aumentado naquelas que apresentaram DA. A AF em geral parece ser insuficiente para se obter um efeito de treino na força e na endurance dos MPP. PALAVRAS CHAVE: PRESSÃO INTRA-ABDOMINAL; MÚSCULOS DO PAVIMENTO PÉLVICO; ATIVIDADE FÍSICA; PREVALÊNCIA; FATORES DE RISCO; INCONTINÊNCIA URINÁRIA DE ESFORÇO; EXERCÍCIO FÍSICO / Urinary incontinence (UI) is a prevalent dysfunction reported by female athletes. Strenuous physical activity (PA) has been identified as a risk factor for UI, whereas moderate PA seems to have a protective effect. However, the impact of different levels of PA on pelvic floor muscle (PFM) function has been scarcely investigated. The aim of this thesis was to assess the prevalence of UI in Portuguese elite female athletes and to identify its potential risk factors. Also, it aimed to clarify the association between PA level and variables of PFM function. Three cross-sectional studies were developed among young and healthy women with different levels of PA. All data were collected by questionnaires, except variables of PFM function that were assessed by manometry. Appropriate statistical analyses were performed, controlling for potential confounders. Study I assessed the prevalence and risk factors for UI among 372 elite athletes from different sports and 372 controls. The association of disordered eating (DE) and UI was assessed in Study II, in the same sample. In Study III, association of different levels of PA and variables of PFM function was explored. The results showed that the odds of UI was three times higher in elite athletes than in controls. Athletes with DE presented increased odds of UI of any type, in comparison to athletes without DE. PA was associated with vaginal resting pressure but not with PFM strength or endurance. In conclusion, athletes competing at elite level are at higher risk for UI than non-athletes, and DE behaviours may increase the risk for UI. General PA seems to be insufficient to achieve a training effect on PFM strength and endurance.